Hydraulic tensioners are typically used as control devices for endless loop power transferring members, such as chain or belt drives, in an automotive engine timing system. Such endless loop power transferring members provide a driving connection from the crankshaft to the camshafts and to auxiliary devices, such as an oil or fuel pump. During typical operation, the tension in the chain or belt can vary greatly due to the dynamic shaft oscillations which are induced from engine firing, valve train loading, or auxiliary device operation. Moreover, chain or belt components typically wear during prolonged use thereby increasing the length of the chain or belt and decreasing the tension on the chain or belt. A hydraulic tensioner is used to take up the slack in the chain or belt and provide control of the chain or belt oscillations due to tension fluctuations.
Hydraulic tensioners are known from U.S. Pat. Nos. 8,021,254; 6,053,831; 5,277,664; 5,259,820; 5,176,581; 5,116,284; U.S. Published Appl. No. 2009/0017949; CN 201575116; EP 1215415; and EP 1022487. While these devices appear to be suitable for their intended purposes, it would be desirable to provide a variable flow hydraulic chain tensioner. It would also be desirable to provide a variable flow hydraulic chain tensioner with simple mechanical construction allowing lower cost of manufacturing, assembly and installation. A variable flow hydraulic chain tensioner of robust, efficient, and dependable performance is also desirable to be provided.